Wall supporting structure



May 13, 1941. K. MARSH WALL SUPPORTING STRUCTURE Filed Aug. 8, 1938 1N VENTOR. D MARsH.

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' KIRTL'AN BY M-w A 3 EERNEY.

Patented May 13, 1941 I is 2,241,822 WALL SUPPORTING STRUCTURE Kirtland Marsh, Pittsburgh, Pa., assignor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Application August 8, 1938, Serial No. 223,596

11 Claims.

This invention relates to an apparatus for yieldably supporting structures such as tanks, and particularly to an adjustable apparatus for yieldably supporting and reinforcing the walls of long, deep tanks for holding liquids and the like for industrial process or storage. It relates more particularly to supporting structures for tanks which are adapted to hold molten salt baths at temperatures as high as 1000 F.

It is a general object of this invention to provide a tank support which will prevent warping and buckling of tank walls, and failure thereof under changes in temperature, pressure, or both.

A further object of this invention is to provide a yieldable support for tanks, and particularly long walls thereof, so as to allow for expansion, contraction, and shifting or change in alignment of component parts caused by changes in temperature, along the length, width,-and height of the tank, and yet to support the tank against internal pressures.

Other objects are. to provide this support in such a manner as to permit the degree .of yieldability to be adjustable, and, where necessary, to 1' permit the tank to be insulated without interfering with the supporting means and to minimize direct heat conduction from the tank to the supporting apparatus. The object in providing adjustable support is to permit setting the reaction pressure of the supporting structure on the tank walls approximately to that amount necessary to neutralize varying hydrostatic pressures in baths of different densities; and to eliminate distortion of the tank ordinarily caused by these varying pressures and by' varying strength and rigidity in the material of the tank itself at different bath temperatures.

It'is recognized that structural metals, even high strength iron or steel, lose much of their strength and rigidity when raised above 750 F. Sheet iron and steel, and the like, adapted to be used in the construction of tanks for nitrate heat treating processes, may be affected in the above mentioned manner to a marked degree at the temperatures ordinarily encountered therein, namely, in the range from 750 to 1000? F. The strength of such material may be affected at even lower temperatures.

A supporting apparatus bearing with constant or unyielding pressure upon the tank walls would itself often cause distortion of the walls, since the pressures of the bath and the changes in temperature of the bath and tank have the effects above-mentioned. For these reasons it has been found'preferable to use the adjustably yieldable support described herein.

Inthe embodiment of the invention chosen for this description, heating of the bath in the tank may be provided by electric immersion heaters; but the bath may be heated by a type of heating apparatus external to the tank. When heated by an apparatus of the latter type, the tank would best be built with relatively thin walls to permit rapid heat transfer. The thinness of these walls would further necessitate the kind of support described herein.

In accordance with the invention, a tank may be supported in a suitable setting or supporting structure which permits it to rest freely on its base while confining it yieldably within buttresses; or a tank may be confined yieldably only at the lower part of the side walls and resiliently anchored near the top to suitable buttresses. This latter structure and method of support will be described as the preferred embodiment of the invention; but yieldable supporting mechanisms also might be used to support the upper part of the tank, including the rim.

The objects of this invention can be attained in the preferred form thereof shown in the attached drawing, in which like reference numerals identify similar parts. Novel constructions and combinations of parts will appear in the specification the spring supporting assemblies with parts broken away to more clearly show the mode of construction.

Referring now to the drawing, a relatively long, Q

deep, rectangular riveted or welded, sheet or cast metal tank I, such as is used in nitrate heattreatment of sheet metal, or the like, is shown resting on a suitable heat-resistant base 2, such as insulating brick, laid onconcrete or other substantial foundation 3. In the preferred form of the invention, adjacent each long side-wall of the tank I, three wall buttresses 4, fabricated from metal structural members, serve as mountings for yieldable supports and resilient anchorages, to be hereinafter described in more detail, acting between the buttresses and the tank walls. These buttresses 4 may be further stabilized in giving support to the tank by connection with end and side insulation retaining plates 5, spaced away from the tank; and the buttresses 4 are tied together at their top portions as by means of the horizontal beams I'I. It will be apparent that similar buttresses could be provided at the ends of the tank I where desired.

ttached, as by welding, to each side wall of tank I at two conveniently spaced vertical positions, preferably below the upper third of the tank, are two horizontal beams 6 running the length of the tank, which beams affect the relative rigidity of the tank and distribute the yieldable supporting forces applied to them in a manner hereinafter described. A third horizontal beam 6 is attached to each side wall of the tank near the rim or within the upper third of the side wall. This latter beam 6 could also be employed to distribute yieldable supporting forces,

applied to it in the same manner as to the other beams 6; but, in this embodiment of the invention, it is primarily employed to strengthen the tank wall and to provide a means for resiliently anchoring the top of the tank side wall to the supporting buttresses 4 Similar horizontal beams 6 lend rigidity to end walls of tank I, as shown in Fig. 1.

The aforementioned yieldable supporting means for the tank walls are mounted in association with the buttresses 4 and intermediate and lower beams 6. Each yieldable supporting means is identical in its construction and parts, and comprises a spring supporting assembly, which is represented in its entirety by the reference numeral I, and is shown to best advantage in Fig. 4. Each spring assembly I incorporates supporting plates 22 secured as by Welding directly to the vertical legs and directly or by means of spacing members 24 to the sloping legs of the buttresses 4 at positions adjacent the lower and intermediate horizontal beams G. In each spring assembly I, suitable tie bolts I5 (four of which are preferred, but only two of which have been shown in Figs, 2 and 4 for simplicity of illustration) extend through the plates 22 and are secured thereto at either end as by nuts I 5a.' A spring positioning seat member I is slidably mounted upon the bolts I5, nuts I6 being provided on threaded portions of bolts I for selectively positioning the seat member IiI'. A loading spring seat member I! is also slidably mounted upon the tie bolts I5, members I0 and I2 embracing and supporting therein a suitable coiled spring II. A load-adjusting screw I3 threadedly engages a nut It, slidable on bolts f5 and normally held in alignment by an integral boss centered in an aperture in the outer plate 22, adjacent the loading spring seat member I2. The loading screw It, in bearing contact with seat member I 2, provides an adjustable means for controlling the maximum length of the spring II between seats It and I2, thereby providing a means for predetermining the initial yieldable pressure exerted by the spring I! upon the seat member Iii.

A spherical or cup-shaped bearing surface Illa is provided in the face of each seat member ID adjacent the tank wall, and a. suitable bearing block 8, provided with a similar spherical or cupshaped bearing surface 8a, is secured, as by welding, to the beam 6 adjacent each bearing surface Iila. A push rod 9, having rounded ends of smaller diameter than the entrance diameter to the bearing surfaces 8a and Ilia, is positioned and received within each pair of aforementioned bearing surfaces Ba and Ilia and serves to transmit the supporting forces of each spring assembly unit I. It may thus be seen that varying degrees of yieldable pressure may be applied directly to the beams 6 through the medium of each spring assembly I by means of adjusting and regulating the loading screw I3.

The aforementioned resilient upper supporting or anchoring means for the tank walls are mounted in association with the buttresses 4 and the top. horizontal beam members 6. Each resilient supporting or anchoring means incorporates a connection between a horizontal beam I1, carried by and at the upper end of the buttresses 4, as by means of rivets 20, and an aforementioned upper beam 6. To impart a resilient and relatively non-heat-conducting connection between the horizontal beams 6 and IT, a resilient wood or composition filler block I8 is employed between the adjacent flanges of these beams, through-bolts I9 being provided to secure the beams and interposed resilient member I8 in secured position. Oversize bolt holes I9a, are provided in beams I! for bolts I9 which are preferably not drawn up tightly. These anchoring connections hold the upper portion or rim of the tank I approximately centrally between the buttresses 4 on opposite sides of the tank; and, as may be apparent, at the same time afford an adequately resilient support for the upper portion of the tank side walls, which are not subjected to the same degree of hydraulic pressure as are the lower portions of the tank side walls.

The space between the tank I and the buttresses 4 and around the ends of the tank is preferably filled with any suitable heat-resistant insulating compound 2|, such as rock wool or the like, plates 5 serving to retain the insulation material within the space. between the shell of the tank and the aforementioned plates 5. A top cover 23 is mounted over and between the tank rim and the top of the buttresses 4; it protects the supporting apparatus and the insulation 2|.

In order that the invention may be more fully understood, the function of the above described structure and a manner of its use may be described in more detail. It will be noted that the cold tank may be located centrally, with clearances, between the buttresses 4 at the top by the resilient upper anchorages consisting of members I'I, I8, I9, and 20. The spring positioning nuts I6 on each spring assembly I on each side of the tank maybe turned, for example, so that each bearing I00 is positioned from each bearing 8a a distance such that push rod 9 may have a clearance within the bearing surfaces Illa and 8a approximately equal to half the previously calculated thermal expansion of the tank when raised to operating temperature. When the spring assemblies are so adjusted on each side, the tank would expand from heat alone when raised to operating temperature, to permit the bearings and the push rods to come into direct acting position, taking up the aforementioned clearance.

After the nuts I6 are adjusted to positionspring seat III, compression adjusting screw It may be turned to position-spring seat I2 so as to give each coil spring II a loaded length previously calibrated to provide a definite loading stress. Thus, when the tank is put into use, the thermal expansion will have been compensated for; and, furthermore, the tendency to expand, due to hydraulic pressure, will have been approximately neutralized by the pre-loaded springs acting on the horizontal beams and the tank.

Loading of the springs II need not necessarily be made before the tank is put into operation, since the adjusting screws l3 are located outside of the buttresses and may be set or re-set While the tank is in use.

Allowance has been made for vertical and horizontal expansion, contraction, and shifting of the tank walls by the provision of spherical or cup-shaped surfaces 8a and Ma on push rod bearing blocks 8 and on the push rod bearings in positioning spring seats I0, whereby the push rods are free to transmit the spring supporting forces, even though the bearings may not be in axial alignment. liiach pair of these bearing surfaces 8a and Illa confines the rounded heads of the push rod 9 in the incurved cavities, which may be provided with entrance'diameters enough larger than the push rod diameter to provide a limited universal action, but which may be small enough and deep enough to maintain the push rods between them at all temperatures and pressures encountered.

The resilient anchorages at the top of the tank, being composed of beams attached toeach other through wood or composition members by loosely drawn bolts IS, in at least one of which beams the holes 49a are oversize, permit much the same limited freedom in expansion, contraction, and shifting.

The insulation 21, between the tank I and the buttresses 4 and side and end plates 5, prevents the heat of the material in the tank from affecting to any great degree the temperature and, therefore, the rigidity of the buttresses. The use of a porous, granular insulating material 21 such as rock wool or the like, allows for any of the aforementioned expansions, contractions, and shiftings of tank walls. Both the push rods 9 and resilient members I8 serve to afford only negligible heat conduction from the tank to the springs or buttresses.

The invention is capable of wide variation and relationship of parts without departure from its nature or principle. It should not be considered restricted, unessentially, in the foregoing or other particulars; but it is contemplated that alterations and modifications within the scope of the appended claims may be found advisable. It is further desirable to point out that the use of this invention is not confined to the kind of tank described in the preferred embodiment, but may be applied to any similar structure requiring yieldable support, as claimed herein.

What is claimed is:

1. A tank supporting structure comprising a plurality of buttresses disposed adjacent walls of a tank, a plurality of spring supporting assemblies mounted on said buttresses, each of said assemblies including an adjustable spring, means for confining the action of said spring relative to the tank and means for loading said spring,

. and means for transmitting spring supporting forces to beams attached to said walls, sai'd beams adapted to distribute said supporting forces over said Walls.-

2. A tank supporting structure comprising a plurality of buttresses disposed adjacent walls of a tank, a plurality of spring supporting assemblies mounted on said buttresses, each of said assemblies including an adjustable spring, means for confining the action of said spring relative to the tank and means for loading said spring, a plurality of beams reinforcing said tank walls, and means for transmitting spring supporting forces to bearing blocks attached to said beams, said beams adapted to distribute supporting forces over said walls.

3. A tank supporting structure comprising supporting members disposed adjacent at least one wall of a tank, a plurality of spring supporting assemblies associated with said supporting members, each of said assemblies including an adjustable spring and means for loading said spring, bearing members having substantially spherical bearing surfaces and adapted to be associated with said tank wall and with said spring assemblies, and substantially round-ended pin members freely engaging said bearing members in said bearing surfaces for applying spring supporting forces to said tank wall.

4. A tank supporting structure comprising a plurality of buttresses disposed adjacent the walls of a tank, a plurality of spring supporting assemblies associated with said buttresses, each of said spring assemblies including an adjustable spring, means for loading said spring and means for confining the action of said spring relative to the tank, and means for transmitting spring supporting forces to said walls.

5. A tank supporting structure comprising a plurality of buttresses disposed adjacent the walls of a tank, a plurality of spring supporting assemblies associated with said buttresses, each of said spring assemblies including an adjustable spring, means for loading said spring and means for positioning said spring relative to the tank, bearing members having substantially spherical surfaces and adapted to be associated with a tank wall and with said spring assemblies, and substantially round-ended pin members freely engaging said bearing members in said bearing surfaces for applying spring supporting forces to said tank wall.

6. A tank supporting structure comprising a plurality of buttresses about the walls of a tank, a plurality of spring supporting assemblies mounted on said buttresses, each of said spring assemblies including an adjustable spring, two seats for said spring, means for selectively positioning one of said seats to confine the action of said spring relative to the tank and means for variably loading said spring, and means for transmitting spring supporting forces to said walls.

'7. In a tank support, a plurality of supporting members spaced from and disposed adjacent a tank, a plurality of spring supporting assemblies associated with said supporting members, each of said spring assemblies comprising an adjustable spring member, two seats for said spring member, one of said seats selectively positionable to confine the movement of said spring member in the direction of its supporting action, the other of said seats adjustably positionable to load said spring member, means for selectively positioning the former of said seats and means for adjustably positioning the latter of said seats, and means for transmitting spring supporting forces from said spring assemblies to said tank comprising bearing members associatedwith said spring assemblies provided with substantially spherical bearingsurfaces, bearing members adapted to be associated with said tank and provided with substantially spherical bearing surfaces, and pin members having substantially round ends f eely en ag n pairs of said bearing member surfaces, said pin members adapted to transmit spring supporting forces between said bearing members.

8. A supporting apparatus comprising a supporting member adapted to be disposed adjacent a member to be supported, a spring supporting assembly associated with said supporting member, including an adjustable spring, means for variably loading said spring and means for confining the action of said spring in the direction of the member to be supported, bearing members having substantially spherical bearing surfaces and adapted to be associated with said member to be supported and with said spring assembly, and a substantially round-ended pin member freely engaging said bearing members in said surfaces for transmitting spring supporting forces between said bearing members.

9. A tank supporting structure comprising at least one supporting member disposed adjacent a wall of a tank, a plurality of spring supporting assemblies associated with said supporting member, each of said spring assemblies including an adjustable spring and means for loading said spring, and means for transmitting the spring supporting forces to said walls, in combination with at least one upper anchorage for the wall of the tank comprising a resilient member-interposed between said tank and said supporting member, and means for freely connecting said tank, resilient member, and supporting member, said supper wall anchorage serving to locate said tank and resiliently support it in cooperation with yieldably supporting spring assemblies.

10. A tank supporting structure comprising a plurality of buttresses about the walls of a tank, a plurality of spring supporting assemblies mounted on said buttresses, each of said assemblies including an adjustable spring and means for loading said spring, and means for transmitting spring supporting forces to said walls, in combination with a plurality of upper anchorages for said tank, comprising reinforcing members attached to said tank, reinforcing members attached to said buttresses, resilient members interposed between said tank reinforcing members and said buttress reinforcing members, and means for freely connecting said reinforcing members and said resilient members, said upper anchorages serving to locate said tank and resiliently support it in cooperation with yieldably supporting spring assemblies.

11. A supporting apparatus comprising a supporting member adapted to be disposed adjacent a member to be supported, means associated with said supporting member for exerting a yieldable pressure on said member to be supported, including an adjustable spring, means for limiting the movement of the end of said spring adjacent said member to be supported toward said member to be supported and means for loading said spring, bearing members having substantially spherical bearing surfaces and adapted to be associated with said member to be supported and with said ,yielda-ble pressure exerting means, and .a substantially round ended pin member freely engaging said bearing members in said surfaces for transmitting spring supporting forces between said bearing members.

KIRTLAND MARSH. 

